Camera module with a variable lens

ABSTRACT

An exemplary embodiment of the present disclosure includes a PCB mounted with an image sensor, a base installed at an upper surface of the PCB to centrally form an optical path, a lens holder coupled to an upper surface of the base to form an optical path by being mounted with at least one or more sheets of lenses, a variable lens arranged on the optical path centrally formed at the base to control a refractive index of passing light, and an infrared cut-off coating layer provided on a surface of the variable lens to filter an infrared component from the optical path-passing light.

Pursuant to 35 U.S.C. §119 (a), this application claims the benefit ofearlier filing date and right of priority to Korean Patent ApplicationNo. 10-2012-0047956, filed on May 7, 2012, the contents of which arehereby incorporated by reference in their entirety.

BACKGROUND OF THE DISCLOSURE

1. Field of Endeavor

The teachings in accordance with exemplary and non-limiting embodimentsof this disclosure relate generally to a camera module.

2. Background

In a case an auto focusing operation is carried out in a conventionalcamera module, an auto focus terminal and a PCB auto focus pad must beconductibly connected to drive an actuator, which is disadvantageouslysusceptible to shock.

Particularly, development of a camera module configured to maintain anauto focusing function and handshake compensation function, and yet tominimize a height of the camera module is required by a user needs to aslimmer camera module installed on small-sized electronic products suchas notebooks, smart phones and tablet personal computers.

SUMMARY OF THE DISCLOSURE

In one general aspect of the present disclosure, there is provided acamera module, the camera module comprising: a PCB (Printed CircuitBoard) mounted with an image sensor; a base installed at an uppersurface of the PCB to centrally form an optical path; a lens holdercoupled to an upper surface of the base to form an optical path by beingmounted with at least one or more sheets of lenses; a variable lensarranged on the optical path centrally formed at the base to control arefractive index of passing light; and an infrared cut-off coating layerprovided on a surface of the variable lens to filter an infraredcomponent from the optical path-passing light.

Preferably, but not necessarily, the camera module may further comprisesan actuator controlling the variable lens.

Preferably, but not necessarily, the lens holder and the base may beintegrally formed.

Preferably, but not necessarily, the infrared cut-off coating layer maybe formed on any one surface of the lenses.

Preferably, but not necessarily, the actuator may include any one of aMEMS actuator moved by using an electrostatic force and a piezoelectricforce, a non-MEMS actuator like a liquid crystal lens and apiezoelectric polymer lens, a silicon type actuator, and a liquid lens.

Preferably, but not necessarily, the actuator may include a combinationof at least two of a MEMS actuator moved by using an electrostatic forceand a piezoelectric force, a non-MEMS actuator like a liquid crystallens and a piezoelectric polymer lens, a silicon type actuator, and aliquid lens.

Preferably, but not necessarily, the actuator may be connected to thePCB via a wiring member to exchange an electric power and a controlsignal.

Preferably, but not necessarily, the wiring member may be provided withan F-PCB (Flat PCB).

Preferably, but not necessarily, the wiring member may be formed with anF-PCB having a plurality of terminal units to be connected to acontroller mounted on the PCB.

Preferably, but not necessarily, the wiring member may be provided withan electronic circuit pattern layer integrally formed with the lensholder and the base.

Preferably, but not necessarily, the lens holder may include at leastone or more sheets of lenses, and an optical mechanism arranged on anoptical path formed by the lens to adjust the passing light.

Preferably, but not necessarily, the optical mechanism may include anaperture and a shutter.

Preferably, but not necessarily, the optical mechanism may be interposedbetween any one space formed by an extreme outer lens supported by theactuator and the lens opposite to the extreme outer lens, a space formedby the image sensor and a lens opposite to the image sensor and a spaceformed by the plurality of lenses.

Exemplary embodiments of the present disclosure have an advantageouseffect in that handshake compensation function and auto focusingfunction can be performed by changes in refractive indexes of passinglight through changes in fixed lens thickness free from horizontal,vertical and tilting movement of a lens, and a height of a camera modulecan be reduced to enable a miniaturization of the camera module.

BRIEF DESCRIPTION OF THE DRAWINGS

In order to explain the principle of the present disclosure, someaccompanying drawings related to its preferred embodiments are belowreported for the purpose of illustration, exemplification anddescription, although they are not intended to be exhaustive. In thefigures, like reference numerals refer to the same or similar elements.

FIG. 1 is a schematic lateral cross-sectional view illustrating a cameramodule according to a first exemplary embodiment of the presentdisclosure.

FIG. 2 is a schematic lateral cross-sectional view illustrating a cameramodule according to a second exemplary embodiment of the presentdisclosure.

FIG. 3 is a schematic lateral cross-sectional view illustrating a cameramodule according to a third exemplary embodiment of the presentdisclosure.

FIG. 4 is a schematic lateral cross-sectional view illustrating a cameramodule according to a fourth exemplary embodiment of the presentdisclosure.

FIG. 5 is a schematic lateral cross-sectional view illustrating a cameramodule according to a fifth exemplary embodiment of the presentdisclosure.

DETAILED DESCRIPTION

Hereinafter, exemplary embodiments of the present disclosure will bedescribed in detail with reference to the accompanying drawings.

FIG. 1 is a schematic lateral cross-sectional view illustrating a cameramodule according to a first exemplary embodiment of the presentdisclosure, FIG. 2 is a schematic lateral cross-sectional viewillustrating a camera module according to a second exemplary embodimentof the present disclosure, FIG. 3 is a schematic lateral cross-sectionalview illustrating a camera module according to a third exemplaryembodiment of the present disclosure, FIG. 4 is a schematic lateralcross-sectional view illustrating a camera module according to a fourthexemplary embodiment of the present disclosure, and FIG. 5 is aschematic lateral cross-sectional view illustrating a camera moduleaccording to a fifth exemplary embodiment of the present disclosure.

Referring to FIG. 1, a camera module according to an exemplaryembodiment of the present disclosure includes a PCB 10, a base 20, alens holder 30, an actuator 40, and a variable lens 41 where the base 20and the lens holder 30 may be integrally formed.

The PCB 10 may be formed with an image sensor 11 at an approximatecenter thereof to read out image information, and may be mounted at asurface thereof with the image sensor 11 and a controller 12 outputtingdata and a control signal of the actuator 40. At this time, the actuator40 and the PCB 10 may be conductibly connected via a wiring member 13,where the wiring member 13 may be provided with an F-PCB (Flexible PCB),or may be formed with an electronic circuit pattern layer formed on asurface of the base 20 by using an Interconnection technology.

The base 20 may be stacked on an upper surface of the PCB 10 to performa function of supporting a structure of the camera module. It ispreferable that the base 20 be stacked at an upper surface with the lensholder 30, the variable lens 41 and the actuator 40 arranged on anoptical path formed at an approximate center thereof, the actuatordownwardly face the image sensor 11 and oppositely face the lens holder30.

The lens holder 30 is centrally and sequentially arranged with at leastone or more sheets of lenses 31 to capture an external image toward theimage sensor 11. At this time, the lenses 31 may be installed in themiddle thereof with a separate optical mechanism 32 including a shutterunit and an aperture, if necessary.

That is, the lens holder 30 may be sequentially arranged with at leastone or more sheets of lenses, and in a case two lenses are arranged onan optical path formed inside the lens holder 30, the aperture and theshutter unit may be arranged at a space between two lenses as shown inthe drawing, at a space between the lens 31 and the actuator 40, or atan upper surface of an extreme outer lens 31 or at a downward of thelens 31. This arranged relationship may be changed in response to aproduct design and configuration of camera unit. Preferably, wiring isconfigured with parts replacing the base 20 and the lens holder 30. Ofcourse, the base 20 and the lens holder 30 may be integrally formed. Inthis case, a process of attaching and fixing the base 20 and the lensholder 30 together may be omitted.

The actuator 40 is fixedly installed on the base 20, and preferably, theactuator 40 downwardly faces the image sensor 11 and oppositely facesthe extreme downward lens 31 among the plurality of lenses 31, asillustrated in the drawing.

The actuator 40 may be used with various structures, and according to anexemplary embodiment of the present disclosure, the actuator 40 may beformed to control one sheet of variable lens 41, where the actuator 40is fixed and needs no movement. At this time, the variable lens 41 maybe configured with an LC (Liquid crystal) lens, a liquid lens or apiezoelectric polymer lens. In the case of these types of lenses, it isunderstood that the control would include providing signals or electricpower to the lens without displacement of the lens.

The present disclosure is characterized by an infrared cut-off coatinglayer 50 configured on any one of the constituent elements forming theactuator 40 thus described to dispense with a separate infrared cut-offfilter member. Thus, a surface opposite to the image sensor 11 of thevariable lens 41 may be formed with the infrared cut-off coating layer50. In a case an infrared cut-off coating function is performed on thevariable lens 41 free from the separate infrared cut-off filter, anassembly process can be reduced, and a height of a camera module can belowered due to no need of a separate infrared cut-off filter.

Meanwhile, FIG. 2 is a schematic lateral cross-sectional viewillustrating a camera module according to a second exemplary embodimentof the present disclosure, where the infrared cut-off coating layer 50is formed on a surface opposite to the lens 31 of the lens holder 30.

In the second exemplary embodiment of the present disclosure, althoughthe infrared cut-off coating layer 50 is formed on a surface of onesheet of variable lens 41 controlled by the actuator 40, as in the firstexemplary embodiment of the present disclosure, only difference is thatposition of the surface is different while other configuration is same.

In other exemplary embodiment of the present disclosure, as illustratedin FIG. 3, it is possible to form the infrared cut-off coating layer 50on a surface of an extreme rear lens of the lens holder 30, and as inFIG. 4, it is possible to form the infrared cut-off coating layer 50 ona surface of a first lens of the lens holder 30, and as in FIG. 5, it ispossible to form the infrared cut-off coating layer 50 on any one lensof the plurality of lenses 31 installed on the lens holder 31.Alternatively, instead of coating on the lens 31, an existing infraredcut-off filter member may be formed inside a space unit. That is, anyone surface of a lens in the plurality of lenses may be coated, or aseparate infrared cut-off filter member may be used.

Meanwhile, although the abovementioned exemplary embodiments of thepresent disclosure have described and illustrated that the actuator 40is formed with the variable lens 41 of an LC lens, and refraction ofpassing light is changed, without physically moving one sheet of lens,to perform auto focusing and handshake compensating functions, it shouldbe apparent that the present disclosure is not limited thereto.

The actuator 40 may be so configured as to perform a zooming functionand +a shutter function in addition to the auto focusing and handshakecompensating functions. Furthermore, the actuator 40 may be replaced byany actuator capable of controlling one sheet of lens such as anactuator using a piezoelectric polymer and movable by usingelectrostatic force or a piezoelectric force.

That is, by way of non-limiting example, the actuator may be any one ofa MEMS (Micro-electromechanical Systems) actuator capable of moving onesheet of lens using the electrostatic force and the piezoelectric force,a MEMS piezoelectric actuator, a MEMS bimorph actuator, an MEMS thermalactuator, a MEMS magnetic actuator, a MEMS liquid actuator, a non-MEMStype actuator, a silicon type actuator, and a liquid lens, or any typeof actuator that is configured by combination thereof.

As apparent from the foregoing according to exemplary embodiments of thepresent disclosure, the infrared cut-off coating layer 50 capable offunctioning as an infrared cut-off filter is arranged on a surface ofthe variable lens 41 to reduce a possibility of a camera module beingdamaged by external shock and to thereby enhance reliability of thecamera module.

Furthermore, a same height as that of a fixed focus camera modulemounted with a conventional infrared cut-off filter can be maintained,or a height lower than that of the fixed focus camera module mountedwith a conventional infrared cut-off filter can be configured, wherebylenses can be co-used for immediate application to the manufacturingprocess.

Still furthermore, instead of disposing an entire camera module duringre-work or occurrence of defects, an error of a relevant part can beselectively corrected to allow management as that of the fixed focuscamera module, and error rate caused by foreign objects that may happenduring the manufacturing process can be reduced to increase a yield rateas that of the fixed focus camera module.

Although the present disclosure has been described with reference to anumber of illustrative embodiments thereof, it should be understood thatnumerous other modifications and embodiments can be devised by thoseskilled in the art that will fall within the spirit and scope of theprinciples of this disclosure.

What is claimed is:
 1. A camera module, the camera module comprising: aprinted circuit board (PCB) mounted with an image sensor; a basedisposed on an upper surface of the PCB to centrally form an opening; alens holder coupled to an upper surface of the base and having aplurality of lenses arranged on an optical path inside the lens holder;a variable lens fixedly arranged between an extreme rear lens of theplurality of lenses in the optical path and the base to changerefractive index of passing light; an actuator disposed between the lensholder and the image sensor to control the variable lens; and aninfrared cut-off coating layer to filter an infrared component from thepassing light, wherein the actuator has a ring shape and is coupled toan inner periphery of the opening formed in the base, wherein theactuator is conductibly connected to the PCB and provides a controlsignal or an electric power for the variable lens, wherein the variablelens is coupled inside the ring-shaped actuator, and wherein a surfaceof any one of the variable lens and the plurality of lenses is coatedwith the infrared cut-off coating layer.
 2. The camera module of claim1, wherein the lens holder and the base are integrally formed.
 3. Thecamera module of claim 1, wherein the actuator includes any one of amicro-electromechanical systems (MEMS) actuator moved by using anelectrostatic force or a piezoelectric force, an actuator for apiezoelectric polymer lens, or a silicon type actuator.
 4. The cameramodule of claim 1, wherein the actuator includes combination of at leasttwo of a micro-electromechanical systems (MEMS) actuator moved by usingan electrostatic force or a piezoelectric force, an actuator for apiezoelectric polymer lens, or a silicon type actuator.
 5. The cameramodule of claim 1, wherein the actuator is connected to the PCB via awiring member to exchange an electric power and a control signal.
 6. Thecamera module of claim 5, wherein the wiring member is provided with aflexible printed circuit board (F-PCB).
 7. The camera module of claim 5,wherein the wiring member is formed with the F-PCB having a plurality ofterminal units to be connected to a controller mounted on the PCB. 8.The camera module of claim 5, wherein the wiring member is provided withan electronic circuit pattern layer integrally formed with the lensholder and the base.
 9. The camera module of claim 1, wherein the lensholder includes an optical mechanism arranged on the optical path formedby the at least one or more lenses to adjust the passing light.
 10. Thecamera module of claim 9, wherein the optical mechanism includes anaperture and a shutter.
 11. The camera module of claim 9, wherein theoptical mechanism is placed in one of a space outside the outermost lensof the plurality of lenses, a space between the plurality of lenses, aspace between the variable lens and a lens of the plurality of lensesneighboring the variable lens, and a space between the image sensor anda lens of the plurality of lenses or the variable lens neighboring theimage sensor.
 12. The camera module of claim 1, further comprising anactuator configured to move the variable lens along the optical path toprovide a zooming function.
 13. The camera module of claim 1, whereinthe infrared cut-off coating layer is formed on a bottom surface of thevariable lens.
 14. The camera module of claim 1, wherein the infraredcut-off coating layer is formed on an upper surface of the variablelens.
 15. The camera module of claim 1, wherein the infrared cut-offcoating layer is formed on a bottom surface of the extreme rear lens.16. The camera module of claim 1, wherein the infrared cut-off coatinglayer is formed on an upper surface of a first lens.